The open source driver is currently not on par with the proprietary driver in terms of 3D performance on newer cards or reliable TV-out support. It does, however, offer better dual-head support, excellent 2D acceleration, and provide sufficient 3D acceleration for OpenGL-accelerated window managers, such as Compiz or KWin.

If unsure, try the open source driver first, it will suit most needs and is generally less problematic (see the feature matrix for details).

Naming conventions

ATI's Radeon brand follows a naming scheme that relates each product to a market segment. Within this article, readers will see both product names (e.g. HD 4850, X1900) and code or core names (e.g. RV770, R580). Traditionally, a product series will correspond to a core series (e.g. the "X1000" product series includes the X1300, X1600, X1800, and X1900 products which utilize the "R500" core series – including the RV515, RV530, R520, and R580 cores).

KMS is enabled by default for autodetected ATI/AMD cards. This section remains for configurations outside stock.

As of Linux 3.9, the radeon driver requires kernel mode-setting (the old user mode-setting can still be enabled as a kernel compile option, however, some features like HDMI audio depend on KMS). If you have radeon.modeset=0 or nomodeset among kernel parameters, remove it. If you have options radeon modeset=0 anywhere in /etc/modprobe.d/, remove it.

Early start

These two methods will start KMS as early as possible in the boot process.

1. Remove all conflicting UMS drivers from kernel command line:

Remove all vga= options from the kernel line in the bootloader configuration file. Using other framebuffer drivers (such as uvesafb or radeonfb) will conflict with KMS.

AGP speed can be set with radeon.agpmode=x kernel option, where x is 1, 2, 4, 8 (AGP speed) or -1 (PCI mode).

If you have a special kernel outside of stock -ARCH (e.g. linux-zen), remember to use a separate mkinitcpio configuration file (e.g. /etc/mkinitcpio-zen.conf) and not /etc/mkinitcpio.conf.

Remove any framebuffer related modules from your mkinitcpio file.

Add radeon to MODULES array in your mkinitcpio file. For AGP support it is necessary to add the AGP driver for your chipset (e.g. intel_agp, ali_agp, ati_agp, amd_agp, amd64_agp, etc.) before the radeon module.

Late start

With this choice, KMS will be enabled when modules are loaded during the boot process.

If you have a special kernel (e.g. linux-zen), remember to use appropriate mkinitcpio configuration file, e.g. /etc/mkinitcpio-zen.conf. These instructions are written for the default kernel (linux).

Note: For AGP support, it may be necessary to add intel_agp, ali_agp, ati_agp, amd_agp, or amd64_agp to appropriate .conf files in /etc/modules-load.d.

Remove all vga= options from the kernel line in the bootloader configuration file. Using other framebuffer drivers (such as uvesafb or radeonfb) will conflict with KMS. Remove any framebuffer related modules from /etc/mkinitcpio.conf. video= can now be used in conjunction with KMS.

Reboot the system.

Performance tuning

The following options apply to /etc/X11/xorg.conf.d/20-radeon.conf.

ColorTiling is completely safe to enable and supposedly is enabled by default. Most users will notice increased performance but it is not yet supported on R200 and earlier cards. Can be enabled on earlier cards, but the workload is transferred to the CPU

Option "ColorTiling" "on"

Acceleration architecture; this will work only on newer cards. If you enable this and then cannot get back into X, remove it.

Option "AccelMethod" "EXA"

Page Flip is generally safe to enable. This would mostly be used on older cards, as enabling this would disable EXA. With recent drivers can be used together with EXA.

Option "EnablePageFlip" "on"

EXAVSync option attempts to avoid tearing by stalling the engine until the display controller has passed the destination region. It reduces tearing at the cost of performance and has been know to cause instability on some chips.
Really useful when enabling Xv overlay on videos on a 3D accelerated desktop. It is not necessary when KMS (thus DRI2 acceleration) is enabled.

Option "EXAVSync" "yes"

Below is a sample config file /etc/X11/xorg.conf.d/20-radeon.conf:

Section "Device"
Identifier "My Graphics Card"
Driver "radeon"
Option "SWcursor" "off" #software cursor might be necessary on some rare occasions, hence set off by default
Option "EnablePageFlip" "on" #supported on all R/RV/RS4xx and older hardware, and set on by default
Option "AccelMethod" "EXA" #valid options are XAA, EXA and Glamor. Default value varies per-GPU.
Option "RenderAccel" "on" #enabled by default on all radeon hardware
Option "ColorTiling" "on" #enabled by default on RV300 and later radeon cards
Option "EXAVSync" "off" #default is off, otherwise on. Only works if EXA activated
Option "EXAPixmaps" "on" #when on icreases 2D performance, but may also cause artifacts on some old cards. Only works if EXA activated
Option "AccelDFS" "on" #default is off, read the radeon manpage for more information
EndSection

Defining the gartsize, if not autodetected, can be done by adding radeon.gartsize=32 into kernel parameters. Size is in megabytes and 32 is for RV280 cards.

Alternatively, do it with a modprobe option in /etc/modprobe.d/radeon.conf:

options radeon gartsize=32

For further information and other options, read the radeon manpage and the module's info page: man radeon, modinfo radeon.

A fine tool to try is driconf. It will allow you to modify several settings, like vsync, anisotropic filtering, texture compression, etc. Using this tool it is also possible to "disable Low Impact fallback" needed by some programs (e.g. Google Earth).

Deactivating PCI-E 2.0

Since kernel 3.6, PCI-E v2.0 in radeon is turned on by default.

It can be unstable with some motherboards, so it can be deactivated by adding radeon.pcie_gen2=0 on the kernel command line.

Glamor

Glamor is a 2D acceleration method implemented through OpenGL, and it should work with graphic cards whose drivers are newer or equal to R300.

Since xf86-video-ati driver-1:7.2.0-1, glamor is automaticaly enabled with radeonsi drivers (Southern Island and superior GFX cards); with other graphic cards you can use it by adding the AccelMethod glamor to your xorg.conf config file in the Device section:

Option "AccelMethod" "glamor"

However, you need to add the following section before:

Section "Module"
Load "dri2"
Load "glamoregl"
EndSection

Warning: Until Xorg Bug 68524 is fixed, glamor will be extremely slow to use with the radeonsi driver.

Hybrid graphics/AMD Dynamic Switchable Graphics

It is the technology used on recent laptops equiped with two GPUs, one power-efficent (generally Intel integrated card) and one more powerful and more power-hungry (generally Radeon or Nvidia). There are three ways to get it work:

If you do not need to run any GPU-hungry application, you can plainly disable the discrete card: echo OFF > /sys/kernel/debug/vgaswitcheroo/switch. You can do more things with vgaswitcheroo (see Ubuntu wiki for more information) but ultimately at best one card is bound to one graphic session, you cannot use both on one graphic session.

You can use PRIME. It is the proper way to use hybrid graphics on Linux but still requires a bit of manual intervention from the user.

Old methods

Dynamic frequency switching

This method dynamically changes the frequency depending on GPU load, so performance is ramped up when running GPU intensive apps, and ramped down when the GPU is idle. The re-clocking is attempted during vertical blanking periods, but due to the timing of the re-clocking functions, does not always complete in the blanking period, which can lead to flicker in the display. Due to this, dynpm only works when a single head is active.

It can be activated by simply running the following command:

# echo dynpm > /sys/class/drm/card0/device/power_method

Profile-based frequency switching

This method will allow you to select one of the five profiles (described below). Different profiles, for the most part, end up changing the frequency/voltage of the GPU. This method is not as aggressive, but is more stable and flicker free and works with multiple heads active.

To activate the method, run the following command:

# echo profile > /sys/class/drm/card0/device/power_method

Select one of the available profiles:

default uses the default clocks and does not change the power state. This is the default behaviour.

auto selects between mid and high power states based on the whether the system is on battery power or not. The low power state is selected when the monitors are in the DPMS-off state.

low forces the gpu to be in the low power state all the time. Note that low can cause display problems on some laptops, which is why auto only uses low when monitors are off.

mid forces the gpu to be in the mid power state all the time. The low power state is selected when the monitors are in the DPMS-off state.

high forces the gpu to be in the high power state all the time. The low power state is selected when the monitors are in the DPMS-off state.

As an example, we will activate the low profile (replace low with any of the aforementioned profiles as necessary):

It depends on which GPU line yours is, however. Along with the radeon driver versions, kernel versions, etc. So it may not have much/any voltage regulation at all.

Thermal sensors are implemented via external i2c chips or via the internal thermal sensor (rv6xx-evergreen only). To get the temperature on asics that use i2c chips, you need to load the appropriate hwmon driver for the sensor used on your board (lm63, lm64, etc.). The drm will attempt to load the appropriate hwmon driver. On boards that use the internal thermal sensor, the drm will set up the hwmon interface automatically. When the appropriate driver is loaded, the temperatures can be accessed via lm_sensors tools or via sysfs in /sys/class/hwmon.

Dynamic power management

With kernel 3.11, ASPM is activated by default but DPM is not. To activate it, add the parameter radeon.dpm=1 to the kernel parameters.

Unlike dynpm, the "dpm" method uses hardware on the GPU to dynamically change the clocks and voltage based on GPU load. It also enables clock and power gating.

There are 3 operation modes to choose from:

battery lowest power consumption

balanced sane default

performance highest performance

They can be changed via sysfs

# echo battery > /sys/class/drm/card0/device/power_dpm_state

For testing or debugging purposes, you can force the card to run in a set performance mode:

HDMI audio

HDMI audio is supported in the xf86-video-ati video driver. By default HDMI audio is disabled in the driver kernel versions >=3.0 because it can be problematic. However, if your Radeon card is listed in the Radeon Feature Matrix it may work. To enable HDMI audio add radeon.audio=1 to the Kernel parameters.

If there is no video after bootup, the driver option will have to be disabled.

As of 2013-09-20, the driver does not support HDMI Audio for Central Islands cards.

If the sound is distorted in PulseAudio try setting tsched=0 and make sure rtkit daemon is running.

Dual Head setup

Independent X screens

Independent dual-headed setups can be configured the usual way. However you might want to know that the radeon driver has a "ZaphodHeads" option which allows you to bind a specific device section to an output of your choice, for instance using:

This can be a life-saver, because some cards which have more than two outputs (for instance one HDMI out, one DVI, one VGA), will only select and use HDMI+DVI outputs for the dual-head setup, unless you explicitely specify "ZaphodHeads" "VGA-0".

Troubleshooting

Artifacts upon logging in

If encountering artifacts, first try starting X without /etc/X11/xorg.conf. Recent versions of Xorg are capable of reliable auto-detection and auto-configuration for most use cases. Outdated or improperly configured xorg.conf files are known to cause trouble.

In order to run without a configuration tile, it is recommended that the xorg-input-drivers package group be installed.

You may as well try disabling EXAPixmaps in /etc/X11/xorg.conf.d/20-radeon.conf:

Adding undetected resolutions

AGP is disabled (with KMS)

If you experience poor performance and dmesg shows something like this

[drm:radeon_agp_init] *ERROR* Unable to acquire AGP: -19

then check if the agp driver for your motherboard (e.g., via_agp, intel_agp etc.) is loaded before the radeon module, see Enabling KMS.

TV showing a black border around the screen

When I connected my TV to my Radeon HD 5770 using the HDMI port, the TV showed a blurry picture with a 2-3cm border around it. This is not the case when using the proprietary driver. However, this protection against overscanning (see Wikipedia:Overscan) can be turned off using xrandr:

xrandr --output HDMI-0 --set underscan off

Black screen with mouse cursor on resume from suspend in X

Waking from suspend on cards with 32MB or less can result in a black screen with a mouse pointer in X. Some parts of the screen may be redrawn when under the mouse cursor. Forcing EXAPixmaps to "enabled" in /etc/X11/xorg.conf.d/20-radeon.conf may fix the problem. See performance tuning for more information.

No desktop effects in KDE4 with X1300 and Radeon driver

A bug in KDE4 may prevent an accurate video hardware check, thereby deactivating desktop effects despite the X1300 having more than sufficient GPU power. A workaround may be to manually override such checks in KDE4 configuration files /usr/share/kde-settings/kde-profile/default/share/config/kwinrc and/or .kde/share/config/kwinrc.

Add:

DisableChecks=true

To the [Compositing] section. Ensure that compositing is enabled with:

Enabled=true

Black screen and no console, but X works in KMS

This is a solution to no-console problem that might come up, when using two or more ATI cards on the same PC. Fujitsu Siemens Amilo PA 3553 laptop for example has this problem. This is due to fbcon console driver mapping itself to wrong framebuffer device that exist on the wrong card. This can be fixed by adding a this to the kernel boot line:

fbcon=map:1

This will tell the fbcon to map itself to the /dev/fb1 framebuffer dev and not the /dev/fb0, that in our case exist on the wrong graphics card.

Some 3D applications show textures as all black or crash

You might need texture compression support, which is not included with the open source driver. Install libtxc_dxtn (and lib32-libtxc_dxtn for multilib systems).

2D performance (e.g. scrolling) is slow

If you have problem with 2D performance, like scrolling in terminal or browser, you might need to add Option "MigrationHeuristic" "greedy" into the "Device" section of your xorg.conf file.